1. Technical Field
The present invention relates to a cold cathode electron source for a field emission display, and more particularly, the present invention relates to a cold cathode electron source apparatus that uses carbon nanotubes to emit electrons by a field emission effect, and to a method for manufacturing the cold cathode electron source.
2. Related Art
A display device that realizes images by exciting a phosphor layer such as a field emission display or a cathode ray tube typically includes an electron emitting source that emits electrons needed to illuminate the phosphor layer. The electron emitting sources can be used to form a flat panel display for a computer, for example.
The two main types of electron emitting sources include the hot cathode electron source and the cold cathode electron source, depending on cathode type. The hot cathode electron source utilizes a heater. The cold cathode electron source can use carbon nanotubes.
We have found that it would desirable to develop an improved, convenient, efficient, and productive cold cathode electron source apparatus having carbon nanotubes, and a method for manufacturing the cold cathode electron source apparatus.
Exemplars of recent efforts in the art of carbon nanotubes include U.S. Pat. No. 6,062,931 for CARBON NANOTUBE EMITTER WITH TRIODE STRUCTURE issued on May 16, 2000 to Chuang et al., U.S. Pat. No. 6,232,706 for SELF-ORIENTED BUNDLES OF CARBON NANOTUBES AND METHOD OF MAKING SAME issued on May 15, 2001 to Dai et al., and European Patent No. EP 1129990A1 for PROCESS FOR CONTROLLED GROWTH OF CARBON NANOTUBES published on 5 Sep. 2001 and issued to Bower et al.
Chuang '931 describes a cold cathode emitter in which a diameter of a gate aperture is temporarily reduced by means of a sacrificial layer. Dai '706 describes a field emission device having carbon nanotubes on a substrate. The European Patent No. EP1129990A1 issued to Bower et al. describes a plasma enhanced chemical vapor deposition.
Electrons are emitted from defects located on wall surfaces of carbon nanotubes. However, such defects cannot be adequately or favorably used when the carbon nanotubes are grown vertically as in certain methods of at least some of the related art described above.
Catalyst metal particles can be present on ends of the carbon nanotubes. However, because the catalyst metal particles interfere with the electron emission of the carbon nanotubes, this limits attempts at increasing an electron density, and also increases a turn-on voltage that initiates electron emission, thereby preventing low voltage driving.
While the above-referenced related art references provide advantages, we note that they fail to adequately provide an improved, convenient, efficient, and productive cold cathode electron source apparatus having carbon nanotubes and a method for manufacturing such a cold cathode electron source apparatus.